Pin Description

Pin Name

I/O

ROM Code

Option

Description

RES

I

¾

Schmitt trigger reset input, active low.

PA0~PA7

I/O

Wake-up*

Pull-high***

Bidirectional 8-bit input/output port. Each bit can be configured as a

wake-up input by an option. Software instructions determine the

CMOS output or Schmitt trigger input with/without pull-high resistor. The

pull-high resistor of each input/output line is also optional.

PB0/PFD

PB1~PB7

I/O

Pull-high**

PB0 or PFD

Bidirectional 8-bit input/output port. Software instructions determine

the CMOS output or Schmitt trigger input with/without pull-high resis-

tor. The pull-high resistor of each input/output line is also optional. The

output mode of PB0 can be used as an internal PFD signal output and

it can be used as a various frequency carrier signal.

VSS

¾¾

Negative power supply, ground

PC0/TMR0

PC1~PC4

PC5/TMR1

I/O

Pull-high*

Bidirectional 6-bit input/output port. Software instructions determine

the CMOS output or Schmitt trigger input with/without pull-high resis-

tor. The pull-high resistor of each input/output line is also optional. PC0

and PC5 are pin shared with TMR0 and TMR1 function pins.

PF0/INT

I/O

Pull-high*

Bidirectional 1-bit input/output port. Software instructions determine

the CMOS output or Schmitt trigger input with/without pull-high resis-

tor. The pull-high resistor of this input/output line is also optional. PF0

is pin shared with the INT function pin.

VDD

¾¾

Positive power supply

OSC1

OSC2

I

O

Crystal

or RC

OSC1, OSC2 are connected to an RC network or Crystal (determined

by hardware option) for the internal system clock. In the case of RC op-

eration, OSC2 is the output terminal for 1/4 system clock.

Note:

²*² Bit option

²**² Nibble option

²***² Byte option

Absolute Maximum Ratings

Storage Temperature ............................

-50°Cto125°C

Operating Temperature...........................

-40°Cto85°C

-100mA

Total Power Dissipation .....................................500mW

Note: These are stress ratings only. Stresses exceeding the range specified under

²Absolute Maximum Ratings² may

cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed

in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.

HT48RA3/HT48CA3

Rev. 1.30

3

October 12, 2007